As we enter a Mars retrograde period, it may be helpful to take a good look at its possible effects on us as Mars does not retrograde very often. In fact, it only moves in retrograde motion once every two years. No other planet retrogrades this infrequently. However, when it is retrograde, its significance seems can be greater due to both its infrequency as well as to the length of time of the retrograde period. In the 2016 period, Mars will be retrograde for 10 weeks, although the cycle itself is much longer than that.